Conventionally, driver models are known that estimate the operation amount by a driver who has been given a target course. For example, driver models are known that feedback the deviation in vehicle predicted position, if a vehicle was to progress as it is in the current vehicle orientation, from a forward gaze point on a target course, and feedback the deviation between yaw angel displacement and a target yaw angle, for computing a steering angle as an operation amount in Japanese Patent Application Laid-Open (JP-A) No. 2005-335588. In such driver models the yaw angle at the forward gaze point, namely, the tangential direction of a target course at the forward gaze point, is detected in order to compute the operation amount.
Furthermore, a driving behavior model is known that is formed with feed forward control of a condition amount relating to road profile, and feedback control relating to a deviation amount of a course from the vehicle movement in JP-A No. 2006-059765. In this driving behavior model a yaw angle differential value of a center line, or the like, is used as the condition amount relating to road profile.
However, in the technology described in JP-A No. 2005-335588, when the driver model is installed to a vehicle and the tangential direction of a target course at the forward gaze point is estimated from image data in a forward direction, there is the problem that the operation amount of a driver cannot be derived with good precision since there is noise contained in the obtained data.
Furthermore, in the technology described in JP-A No. 2006-059765, the driver model is installed to a vehicle, and when the yaw angle derivative value of the center line is estimated from the image data in a forward direction, there is the problem that the operation amount of a driver cannot be derived with good precision since there is noise contained in the obtained data.